How to find out camera viewable area from architect drawing

[speeder_02 0]

I believe this is a design question and I'm posting here as I need help with a CCTV system implementation. I'm not in the installation stage yet just planning stage. So hope this is the correct place to post a message for help.

 

I have a room that would contain stationary items which are display pieces of sorts; that need to be monitored either in the center of the room or up against the wall. Or both.

 

I'm familiar with computer networks and been tasked to come up with a proposal for a CCTV system. So this is completely a new area for me. I've done some research but still not fully knowledgeable yet or far from it and need help.

 

I've provided jpeg files for illustration. This is reproduced work I've taken out from a part of an architect drawing passed on to me to place the security cameras onto. I just can't figure out how to wrap my head around how to find what area within the box (room) is the viewable area that the camera can cover. I want to know where the blind spots are. I've provided the measurements, can I use these measurements to find out the best viewable area. The length of the room is 11 meters in width roughly, 3.8 meters between the columns which will be the length. The height which I'm taking in as the floor to the ceiling is 4.2 meters.

 

My initial design had four cameras that assumed a viewing angle of 75 degrees. Looking at the angles I've drawn in red are done free hand. I did it just to get a rough idea of the viewing area unless someone can educate me on a better way by providing a formula or method with out much jargon if possible.

 

But after getting opinions I was asked to reduce the amount of cabling needed as the skirt to hide the cabling can accommodate so many cables. So then I looked into 180 degree cameras. So now I need input on if using a 180 degree viewing lens is suited for the room dimensions given before investing in these expensive cameras. The models I am interested in are provided below with links. My plan is to have two of these cameras mounted onto the two columns shown in the diagram. The reason for not having one is I don't believe its 180 degree viewable area but close to 175 degree viewable area. If so then placing a camera on the opposite end should eliminate the blind spot. That's the idea anyway. So should I use 75 or 90 degree viewable cameras or can I also implement 180 degree cameras as well. Wish to hear better ways of implementation as well if any one has any ideas.

 

Inputs anyone. Thanks.

 

Hemispheric Q24M: http://www.mobotix.com/eng_AU/Support/Demos/Hemispheric-Views?tab=72835

Panorama Q24: http://www.mobotix.com/eng_AU/Support/Demos/Hemispheric-Views?tab=74538

[survtech 0]

Camera placement is at least as much an art as it is a science. That is the problem: too many variables in the equation - ceiling height and design, obstacles and obstructions, field of view and a knowledge of what areas are the most critical and how best to cover them are factors that require experience and a lot of often-unavailable information.

 

The best way to lay out a camera system is with a thorough site survey by someone with experience in that application. 2D, and even 3D CAD designs typically can't provide that level of detail.

 

It's difficult, if not impossible, to accurately lay out a project on paper (at least not exact locations) but experience can give planners at least enough ability to get a camera count and cable requirements for bidding on a project. I would still allow a buffer to accommodate unforeseen problems that would have been noted in a true site survey, like aisles blocked by displays or signs hung from the ceiling.

[speeder_02 0]

Thanks for your reply survtech.

 

I agree with what you said, but I am interested in seeing if some general guide lines could be given. You've stated some, you mentioned to take a site visit. Since this is my first project in this nature I've requested early on in design stage that at some point I wish to have access to the site. I believe too in site inspection and done them when drawing up a network design to be implemented into a building. So I'll be going to see the site soon in a couple of days. Construction is ongoing so there will be no way to identify objects that will be placed in rooms as this will be done later. Additional the room environment is such a way that every month or every six month furniture and display items will be removed or replaced with new items.

 

Either way for example if they do hang up signs which are unlikely it can't be a fault of our own. I thinking placing the camera at the highest point on the ceiling would mean most furniture or objects in the room would not interfere with camera surveillance.

 

But let’s take out some of these variables such as obstacles and obstructions i.e. furniture and display items. I know the values for these variables ceiling height 4.2 meters, width 11 meters and length 4 meters. By placing a camera in each corner of the room which will have a 90 degree viewing angle is better than only having three or two cameras right? Cant that be said at least?

 

I managed to find what the area that can be covered with an 180 degree camera I wish to use. In a PDF document for the 24M Hemispheric 3.1 Megapixels mentions that it allows for

 

"monitoring an entire room (10 m x 10 m) using only one single Q24 and saving the data as a high-resolution video sequence."

 

So this camera would be ideal when trying to reduce the number of cameras and cabling right? So I can place two of these cameras on either side of the room to cover the blind spots as I stated in my first post I'm not sure if I can see a 180 degree view but more like 175 degree. As the width of the room in question is 11 meters wide; can one state this camera would fit the bill? But since the length is only to be covered is about 4 meters will this be a problem or not?

 

Anyway the most important thing I posted onto the form was to see if anyone could state that using an 180 degree was the wrong way to go about it and that four 90 degree viewing cameras would be better for reasons stated. Are 180 cameras now being used to replace 4 or 2 cameras in a room? Has there been a good response towards 180 and 360 degree camera technology or do people in the industry prefer 90 degree viewing angle or is it the latter?

 

Thanks.

 

Link to PDF file for 24M Hemispheric Cammera: http://www.mobotix.com/eng_AU/file/1594100/mx_TS_q24sec_en_090615.pdf